class Student:
    
    def __init__(self,id,name,age):
        self.id=id
        self.name=name
        self.age=age

    def __str__(self):
        return '学号: %s 姓名：%s  年龄：%s' %(self.id,self.name,self.age)

    def hell0_student(self):
        print("hell0_student")

stu=Student('1',2,3)
print(stu)